时间:2018-12-07 作者:英语课 分类:(科普英语)Earth and Sky


英语课



Raindrops 雨滴

From a light rain to a heavy downpour, raindrops fall to Earth's surface. And if you watch over time, you'll see that some raindrops are small and some much larger. Find out why -- on today's Earth and Sky.

DB: This is Earth and Sky, with a question from a listener: "What determines the size of raindrops? Sometimes it's a real fine mist, and other times it's big drops."

JB: A mist isn't technically 1 rain, although many people use the word to indicate a light rain. A mist or fog is a cloud on the ground -- and clouds are made up of very tiny water droplets 2. These droplets are smaller than the radius 3 of a human hair -- too small to fall through the atmosphere as rain.

DB: It takes about a million tiny droplets of mist to make one average-sized raindrop. The drops become raindrops by colliding and coalescing 4 with each other in the cloud. If the drops get large enough, they fall as rain. The longer the drops stay in the clouds, the larger they're able to grow.

JB: And that's where the type of cloud that produces the raindrop comes in. Inside of high puffy cumulus clouds, winds are strong. Drops are buffeted 5 by the winds and suspended in the cloud long enough to grow very large.

DB: Then there are stratus clouds -- the relatively 6 low, often uniformly gray clouds. Winds inside these clouds are relatively weak. Raindrops that fall from these clouds may be very small -- because they fall before they've have a chance to grow.

JB: That's today's show, made possible by the National Science Foundation. And, by the way, to ask your Earth or sky question come see us at earthsky.org. I'm Joel Block, with Deborah Byrd, for Earth and Sky.


1 technically
adv.专门地,技术上地
  • Technically it is the most advanced equipment ever.从技术上说,这是最先进的设备。
  • The tomato is technically a fruit,although it is eaten as a vegetable.严格地说,西红柿是一种水果,尽管它是当作蔬菜吃的。
2 droplets
n.小滴( droplet的名词复数 )
  • Droplets of sweat were welling up on his forehead. 他额头上冒出了滴滴汗珠。 来自辞典例句
  • In constrast, exhaled smoke contains relatively large water droplets and appears white. 相反,从人嘴里呼出的烟则包含相当大的水滴,所以呈白色。 来自辞典例句
3 radius
n.半径,半径范围;有效航程,范围,界限
  • He has visited every shop within a radius of two miles.周围两英里以内的店铺他都去过。
  • We are measuring the radius of the circle.我们正在测量圆的半径。
4 coalescing
v.联合,合并( coalesce的现在分词 )
  • A mental model begins coalescing in their minds. 一个意识模型开始结合到他们的脑子里。 来自互联网
  • On the basis of coalescing this kind of element can separate oil from compressed air. 采用凝聚原理,分离压缩空气中的油份。 来自互联网
5 buffeted
反复敲打( buffet的过去式和过去分词 ); 连续猛击; 打来打去; 推来搡去
  • to be buffeted by the wind 被风吹得左右摇摆
  • We were buffeted by the wind and the rain. 我们遭到风雨的袭击。
6 relatively
adv.比较...地,相对地
  • The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
  • The operation was relatively painless.手术相对来说不痛。
学英语单词
abamperes
Alfredia acantholepis
Allium sacculiferum
anaerobe
anaphylactic intoxication
aquae redestillata
assistant principal
attention-seekings
background luminance sensor
be all one to
blueishest
burrises
can't-wait
censorizing
co-managements
commandists
corticopupillary reflex
coyves
decay-affected selectivity
deluging
dentate fissure
development threshold
DEVGRU
dopiest
Downtownian
eccrine angiomatous nevus
electropneumatic positioner
english departments
estivoautumnal(malaria)
evenly distributed
federal governments
filling area
Fluoromebendzole
foraminite
furuncular diathesis
goddang
hanging down
having in
hear warning bells
heliozoans
Hydraulic Rams
hydrolytic cleavage
impropriety
in-yede
intracluster medium
island delta
kammes
Karagaylinskiy
lease-backs
leslie cheung
mass storage disc
Maytiguid I.
mel'nikov
membrane of stapes
microdicks
midgardsormen
mixture optimum
mournfullest
Myorelaxin
myselfe
nephelite (nepheline)
non-H share Mainland private enterprise
not ready for prime time
obsolete activity
ore extraction
ossa Sylvii
paper document
Passate
photodimer
plane up
population pyramid
portery
Pretty Prairie
progressive atrophe of bone
protective legislation
protohominids
pycnometric method
quantum energy table
reciprocating expansion-engine
resin blush
right side engine
sales van
scale trace
scribbling
single spark-plug ignition
sinistrality
solid nibium electrolytic capacitor
straight-line type automatic sampler
strong army horse
submarginally
subvariance
suppression of image signal
the KKK
the top flight
unvisored
Valkeala
vibrating-reed meter
When I die,the world dies with me.
When this is prescribed
whistlin
White's operation
Yambean